Solartron 1287 - Reject; I Reject; LP Filter

CONDITION
The measured celi voltage
and current outputs
of the
SI 1287 can be conditioned
so that
useful
information
is emphasised in relation to noise and signal offsets.
The
facilities available for this are listed in Section 13.
6.1
{V
REJECT}
>>
Remote
command
for Voltage
Bias Rejection is
VT7.
Refer to Chapter
4,
Section 6.12.
Voltage Bias Rejection may be
used to cancel out the d.c. component of
the
measured
voltage output of the SI 1287. This allows a more sensitive FRA
range
to be used and thus improves the measurement accuracy. The level
of bias
rejection may be entered automatically or
as a
fixed value.
[auto]
Select prior to a single measurement, then switch on (using the Bias
Reject
action key) and
perform
the measurement. The d.c. bias detected
during that
measurement is rejected from all later readings.
Assumes no subsequent drift of
d.c.
bias.
[fixed]
Allows
a specific d.c. bias reject value (V VAL) to be entered
for use
when
required.
6.2
{I REJECT}
>>
Remote command
for Current Bias
Rejection
is IT/. Refer to Chapter
4,
Section
6.12.
Current Bias
Rejection. As for {V Reject} but operating on the
current
measurement
channel.
Note: The
[fixed] current bias rejection value selected (I VAL) must be within
the
range dictated by the standard resistor in
use, as
given in
the
section
2.1.
6.3
{LP
FILTER}
> >
Remote command for the Low
Pass
Filter is
FI/.
Refer
to Chapter
4,
Section
6.
12
.
A 10Hz low-pass filter may be switched into the measured voltage
and current
outputs. This reduces wideband noise in low
frequency and d.c. measurements
and allows
the more sensitive FRA ranges to be used for improved measurement
accuracy. Do not filter a signal of frequency greater than
5Hz, however,
otherwise it will be attenuated.
JWS
/
SI1 287 User
Guide I Issue AF
3.15